Semiconductor structures are provided. The semiconductor structure includes a substrate and a first fin structure and a second fin structure formed over the substrate. The semiconductor structure further includes an isolation structure formed around the second fin structure and covering the first fin structure and a gate structure formed over the first fin structure and the second fin structure. The semiconductor structure further includes the first fin structure has a first height and the second fin structure has a second height higher than the first height, and the gate structure and the first fin structure are separated by the isolation structure.
Legal claims defining the scope of protection, as filed with the USPTO.
1. A semiconductor structure, comprising: a substrate; a first fin structure and a second fin structure formed over the substrate; an isolation structure formed around the second fin structure and covering the first fin structure; and a gate structure formed over the first fin structure and the second fin structure, wherein the first fin structure has a first height and the second fin structure has a second height higher than the first height, and the gate structure and the first fin structure are separated by the isolation structure.
2. The semiconductor structure as claimed in claim 1 , wherein the first fin structure has blunt corners at its top portion.
3. The semiconductor structure as claimed in claim 1 , further comprising: an oxide structure formed over the first fin structure; and a first sidewall layer formed on a sidewall of the oxide structure, wherein the first sidewall layer further extends onto a sidewall of the first fin structure.
4. The semiconductor structure as claimed in claim 3 , wherein the first sidewall layer is in direct contact with the gate structure.
5. The semiconductor structure as claimed in claim 4 , wherein the first sidewall layer is a nitride layer.
6. The semiconductor structure as claimed in claim 3 , further comprising: a second sidewall layer formed over the first sidewall layer, wherein the first sidewall layer and the second sidewall layer are both in direct contact with the gate structure.
7. The semiconductor structure as claimed in claim 6 , wherein the first sidewall layer is made of oxide and the second sidewall layer is made of nitride.
8. A semiconductor structure, comprising: a substrate; a first fin structure and a second fin structure formed over the substrate; an isolation structure formed around sidewalls of the second fin structure; and a gate structure formed over the first fin structure and the second fin structure, wherein the first fin structure has a first height and the second fin structure has a second height higher than the first height, and the first fin structure has blunt corners at its top portion.
9. The semiconductor structure as claimed in claim 8 , wherein the top portion of the first fin structure is covered by the isolation structure.
10. The semiconductor structure as claimed in claim 8 , further comprising: an oxide structure formed over the first fin structure, wherein the oxide structure is positioned between the first fin structure and the isolation structure.
11. The semiconductor structure as claimed in claim 10 , further comprising: a first sidewall layer formed on sidewalls of the first fin structure, sidewalls of the oxide structure, and the sidewalls of the second fin structure.
12. The semiconductor structure as claimed in claim 11 , wherein the first sidewall layer is in direct contact with a bottom surface of the gate structure.
13. The semiconductor structure as claimed in claim 12 , wherein the first sidewall layer is a nitride layer.
14. The semiconductor structure as claimed in claim 10 , wherein the oxide structure is in contact with a bottom of the gate structure.
15. A semiconductor structure, comprising: a substrate; a first fin structure and a second fin structure formed over the substrate; an oxide structure formed over the first fin structure; an isolation structure formed adjacent to the second fin structure and covering the oxide structure; and a gate structure formed over the isolation structure and extending across the second fin structure, wherein the gate structure and the first fin structure are separated by the isolation structure.
16. The semiconductor structure as claimed in claim 15 , wherein the first fin structure has blunt corners at its top portion.
17. The semiconductor structure as claimed in claim 15 , further comprising: a first sidewall layer extending onto a sidewall of oxide structure, a sidewall of the first fin structure, and a sidewall of the second fin structure.
18. The semiconductor structure as claimed in claim 17 , further comprising: a second sidewall layer formed over the first sidewall layer, wherein the first sidewall layer and the second sidewall layer are both in direct contact with the gate structure.
19. The semiconductor structure as claimed in claim 15 , wherein a bottom surface of the gate structure is in direct contact with the second fin structure.
20. The semiconductor structure as claimed in claim 15 , wherein the oxide structure is in direct contact with the gate structure.
Cooperative Patent Classification codes for this invention. Click any code to explore related patents in that topic.
May 18, 2017
December 25, 2018
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